World Steel Tube News report Responding to concerns raised by federal investigators looking into the August fire at Chevron's Richmond refinery, company officials say replacement pipe being installed at the plant will resist the type of corrosion that led to the blaze.
Investigators with the U.S. Chemical Safety Board have pressed Chevron officials to justify their selection of pipe made with a metal alloy known as 9 Chrome to replace the carbon-steel pipe destroyed in the Aug. 6 blaze.
World Steel Tube Learn The federal agency warned Chevron that 9 Chrome pipe at a BP refinery near Bellingham, Wash., was badly damaged by corrosion before springing a leak in February, sparking a fire that caused extensive damage. Chevron responded Wednesday, saying in an analysis to Richmond officials that its new pipe not only meets "all industry and fire safety standards" but would resist the type of corrosion that caused the August fire.
Official test results are still pending, but the company has said the blaze was caused by high-temperature, sulfur-heavy crude corroding away the carbon-steel pipe, which was low in protective silicon.
World Steel Tube Learn The company said in October that it would install 9 Chrome, a metal alloy higher in a key corrosion-fighting component, chromium. Federal investigators noted that a third type of pipe material, stainless steel, is even higher in chromium than 9 Chrome. Chevron's internal guidelines dealing with pipeline replacement and inspections refer to stainless steel pipe as being immune to sulfur-related corrosion.
World Steel Tube Learn Richmond officials are holding up the permit process for the refinery reconstruction until the matter is sorted out, Chevron says, potentially jeopardizing the company's plans to have the plant back in full operation in January. City officials say independent experts will review the company's latest analysis before Richmond decides whether to grant more permits.
Permits sought this week
World Steel Tube Learn Chevron has told officials it will have to suspend repairs and lay off as many as 600 workers if it doesn't get needed permits by Thursday.
In an analysis posted last week on the city's website, Chevron senior materials engineer Ned Niccolls and refinery business manager Barbara Smith said 9 Chrome is best suited to combat corrosion caused by sulfur-laden oil.
World Steel Tube Learn The February fire at the BP plant in Washington state "may seem relevant" to the Richmond incident but was not "analogous," they said.
That's because oil in the failed BP line was stagnant, allowing corrosive materials to build up and ultimately cause it to rupture, the Chevron officials wrote. Pipes made of 9 Chrome that have oil flowing through them consistently have not failed, they said.
Fears over stainless steel
World Steel Tube Learn Stainless steel could "introduce a new damage mechanism" at the refinery, the Chevron officials wrote. Salts and acid in oil and the surrounding vapor at the refinery can cause stainless steel lines to succumb to stress corrosion cracking, which the company says is far less predictable than sulfur corrosion. The officials said 9 Chrome is immune from that damage.
World Steel Tube Learn "A final but vitally important consideration in selecting materials for a particular service is the ability to monitor the equipment against damage mechanisms," the Chevron officials said. "A key reason for the selection of 9 Chrome is its predictable corrosion rate, which makes monitoring" more effective.
World Steel Tube Learn But industry standards suggest that sulfur corrosion is unpredictable as well, and Chevron's line failed in Richmond even though it had been inspected three times in one year, federal investigators have said.
U.S. requests documents
World Steel Tube Learn The Chemical Safety Board's general manager, Daniel Horowitz, said Chevron has yet to comply with a Dec. 7 subpoena for documentation about its 9 Chrome decision.
"We don't view it as the board's role to make a specific recommendation about what alloy Chevron should use," Horowitz said Friday. "However, we are looking at how the overall process can be improved in the future with greater transparency and oversight."
World Steel Tube Learn Horowitz said the federal board is "awaiting detailed responses from Chevron about the basis for their selections" of piping material. "We have sent them document requests and interrogatories, and they have not responded. They have promised us a schedule for compliance next week."
World Steel Tube Learn Chevron officials said senior refinery managers met with board officials Thursday in Washington, D.C. They did not say what the outcome of the talks was.
The Richmond City Council is expect to discuss the permit issue Tuesday.
Jaxon Van Derbeken is a San Francisco Chronicle staff writer.World Steel Tube Learn